Simplify the following expression: $z = \dfrac{-1}{6p} + \dfrac{-9}{6p}$
Explanation: Since the expressions have the same denominator we simply combine the numerators: $z = \dfrac{-1 - 9}{6p}$ Combine like terms: $z = \dfrac{-10}{6p}$ Simplify by dividing numerator and denominator by 2: $z = \dfrac{-5}{3p}$